JP4938406B2 - Color filter and liquid crystal display device including the same - Google Patents

Description

  The present invention relates to a color filter used in a color liquid crystal display device and a liquid crystal display device including the color filter.

A color liquid crystal display device is basically sealed between a first transparent substrate on which a first transparent electrode layer is formed, a second transparent substrate on which a second transparent electrode layer is formed, and a gap between them. The color filter is usually formed between the second transparent substrate and the second transparent electrode. First and second polarizing plates are provided outside the first and second transparent substrates, respectively, and a backlight unit including a backlight light source is provided outside the first polarizing plate. .
In such a liquid crystal display device, the voltage applied between the first and second transparent electrode layers is adjusted for each filter segment, and the degree of polarization of light from the backlight unit that has passed through the first polarizing plate is controlled. The display is performed by controlling the amount of light passing through the second polarizing plate. Therefore, the color characteristics of the color filter and the polarizing plate are important factors that determine the color characteristics of the liquid crystal display device.

A color filter has a black matrix, which is a light shielding pattern, and red, green, and blue fine band (striped) filter segments arranged in parallel or intersecting on the surface of a transparent substrate such as glass, or a fine filter. It is composed of filter segments arranged in a constant arrangement.
In recent years, liquid crystal display devices have been evaluated for space saving, light weight, and power saving due to their thinness, and their applications are rapidly expanding to large televisions and monitors. The demand for higher brightness, higher color reproducibility, and higher contrast is increasing for color filters that determine the color characteristics.

As a means for high color reproduction, it is effective to provide a color filter with a fourth filter segment in addition to the red, green, and blue filter segments. It is advantageous to use an advantageous yellow filter segment.
By reproducing the color with four color filter segments, the color reproduction range can be expanded compared to the color filter composed of three colors, and the color filter can be obtained by adding yellow, which has higher luminance than red, green and blue. The brightness can be increased.

However, in the color filter composed of four colors as well as the color filter composed of three colors, the parallel transmitted light of the color filter is caused by the influence of the polarizing plate (the state in which the polarization axes of the two polarizing plates are parallel to each other) The chromaticity of the transmitted light in “Nicol” and the chromaticity of the orthogonal transmitted light (transmitted light that leaks slightly in “Cross Nicol” in which the polarization axes of the two polarizing plates are orthogonal to each other: leaked light) Due to the difference, the color characteristics at the time of white display and the color characteristics at the time of black display in the liquid crystal display device are different, and there is a problem that the color is visible at the time of black display and visibility is inferior. As a result, it has been difficult to obtain sufficient display quality as a liquid crystal display device.
JP 2001-194658 A JP 2002-214436 A JP 2005-316439 A

  Accordingly, the present invention provides a color filter that has high luminance and high color reproducibility, and excellent in visibility without being different from the color characteristics during white display and the color characteristics during black display of a liquid crystal display device. An object of the present invention is to provide a liquid crystal display device.

The color filter of the present invention is a color filter having red, green, blue and yellow filter segments, and the color filter is sandwiched between two polarizing plates, and the chromaticity coordinates (x , Y), the chromaticity (x _P , y _P ) of the parallel transmitted light and the chromaticity (x _C , y _C ) of the orthogonal transmitted light satisfy the following formula (1).
Δxy = [(x _P −x _C ) ² + (y _P −y _C ) ² ] ^1/2 <0.260 (1)
In addition, the liquid crystal display device of the present invention includes the color filter of the present invention.

In the color filter of the present invention, the chromaticity (x _C , y _C ) of orthogonal transmitted light is chromaticity a (0.180, 0.180) and chromaticity on the xy plane in the XYZ color system chromaticity diagram. a straight line connecting b (0.270, 0.180), a straight line connecting chromaticity b and chromaticity c (0.320, 0.250), chromaticity c and chromaticity d (0.380, 0.280) A straight line connecting chromaticity d and chromaticity e (0.400, 0.430), a straight line connecting chromaticity e and chromaticity f (0.300, 0.350), and a chromaticity f and chromaticity It is preferable that it exists in the area | region enclosed by the straight line which connects a.

The contrast ratio of the color filter of the present invention is preferably 2000 or more, and the contrast ratio of the red, green, blue, and yellow filter segments preferably satisfies the following expressions (2) and (3).
CB / CY ≧ 0.60 (2)
CG / CR ≧ 0.60 (3)
CB: Contrast ratio of blue filter segment
CY: Contrast ratio of yellow filter segment
CG: Contrast ratio of green filter segment
CR: Contrast ratio of red filter segment

Further, in the color filter of the present invention, the contrast ratio of the yellow filter segment is preferably 2000 or more, and the yellow filter segment is composed of a dye carrier comprising a transparent resin, a precursor thereof, or a mixture thereof, and a specific surface area according to the BET method. Is 90 m ² / g or more, and is preferably formed from a yellow coloring composition containing at least one kind of yellow pigment selected from CI Pigment Yellow 138, 139, 150, and 185.

  Since the color filter of the present invention has a small difference between the chromaticity of parallel transmitted light and the orthogonal transmitted light measured between two polarizing plates, a liquid crystal display device is formed using the color filter of the present invention. By doing so, it is possible to obtain a high-quality liquid crystal display device having good color reproducibility of white display and black display and excellent visibility.

First, the color filter of the present invention will be described.
The color filter of the present invention includes red, green, and blue filter segments, and the chromaticity coordinates (x, y) of the XYZ color system chromaticity diagram are measured with the color filter sandwiched between two polarizing plates. In this case, the chromaticity (x _P , y _P ) of the parallel transmitted light and the chromaticity (x _C , y _C ) of the orthogonal transmitted light satisfy the following formula (1).
Δxy = [(x _P −x _C ) ² + (y _P −y _C ) ² ] ^1/2 <0.260 (1)

A liquid crystal display device formed using a color filter in which Δxy is within the above range has no difference in color characteristics during white display and color characteristics during black display, and has excellent visibility. When Δxy is 0.260 or more, neutral black cannot be expressed at the time of black display, for example, it tends to exhibit blue or magenta taste, and the visibility of black display becomes very poor.
In order to further improve the visibility of black display, Δxy is preferably less than 0.200, more preferably less than 0.170, and most preferably 0.

The chromaticity (x _P , y _P ) of parallel transmitted light and the chromaticity (x _C , y _C ) of orthogonal transmitted light in the XYZ color system chromaticity diagram with the color filter sandwiched between two polarizing plates are Measured with a color luminance meter under the condition of 2 ° visual field (CIE1931 color system). The light source has an emission spectrum as shown in FIG. 1, luminance = 1937 cd / m ² , and chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.316, 0.301). ), Color temperature = 6525K, and chromaticity deviation duv = −0.0136. In addition, NPF-SEG1224DU (manufactured by Nitto Denko Corporation) is used as the polarizing plate.

A color filter having Δxy in the above range can be obtained by adjusting the contrast ratio of the blue and yellow filter segments constituting the color filter so as to satisfy the following expression (2).
CB / CY ≧ 0.60 (2)
CB: Contrast ratio of blue filter segment
CY: Contrast ratio of yellow filter segment CB / CY is more preferably CB / CY ≧ 1.00, and more preferably CB / CY ≧ 1.50. Note that the upper limit of CB / CY is about 6.00 considering the realizable contrast ratio of the filter segments of each color.

In order to eliminate the difference in color characteristics during white display and black display of the liquid crystal display device and to suppress coloring during black display, the chromaticity (x _C , y _C ) of the orthogonal transmitted light of the color filter is On the xy plane in the XYZ color system chromaticity diagram, as shown in FIG. 2, a straight line connecting chromaticity a (0.180, 0.180) and chromaticity b (0.270, 0.180), A straight line connecting chromaticity b and chromaticity c (0.320, 0.250), a straight line connecting chromaticity c and chromaticity d (0.380, 0.280), chromaticity d and chromaticity e (0.20). 400, 0.430), a straight line connecting chromaticity e and chromaticity f (0.300, 0.350), and a region surrounded by a straight line connecting chromaticity f and chromaticity a. . Outside this range, the correlated color temperature becomes remarkably low, or the deviation from the black body locus becomes remarkably large, so that coloring is felt. The chromaticity (x _C , y _C ) of the orthogonal transmitted light of the color filter is more preferably a straight line connecting the chromaticity a (0.220, 0.220) and chromaticity b (0.280, 0.210), A straight line connecting chromaticity b and chromaticity c (0.330, 0.270), a straight line connecting chromaticity c and chromaticity d (0.370, 0.300), chromaticity d and chromaticity e (0.3. 390, 0.415), a straight line connecting chromaticity e and chromaticity f (0.310, 0.350), and a region surrounded by a straight line connecting chromaticity f and chromaticity a, and more preferably Is a straight line connecting chromaticity a (0.250, 0.250) and chromaticity b (0.280, 0.220), a straight line connecting chromaticity b and chromaticity c (0.330, 0.290), A straight line connecting chromaticity c and chromaticity d (0.365, 0.320), a straight line connecting chromaticity d and chromaticity e (0.380, 0.405), chromaticity e and chromaticity f (0.3. 320, 0.350) It is within the region surrounded by the straight line connecting the straight line and the chromaticity f and the chromaticity a.

The contrast ratio of the color filter of the present invention is preferably 2000 or more, more preferably 3000 or more, and further preferably 4000 or more. When the contrast ratio is less than 2000, when the liquid crystal display device is used, light scattered by the color filter leaks, resulting in an image display lacking sharpness and image quality may be insufficient.
The upper limit of the contrast ratio of the color filter can be increased to the same as the contrast ratio of the polarizing plate (contrast ratio measured without the color filter), and the contrast ratio of the polarizing plate is currently about 15000.

In order to suppress the difference between the color characteristics at the time of white display and the color characteristics at the time of black display of the liquid crystal display device, the contrast ratio of the red and green filter segments constituting the color filter of the present invention is expressed by the following formula (3). It is preferable to satisfy.
CG / CR ≧ 0.60 (3)
CG: Contrast ratio of green filter segment
CR: Contrast ratio of red filter segment CG / CR is a value mainly related to the deviation between the chromaticity of the orthogonally transmitted light of the color filter and the black body locus, and is preferably higher. CG / CR is more preferably CG / CR ≧ 1.00, and further preferably CG / CR ≧ 1.50. The upper limit of CG / CR is about 7.00 in consideration of the realizable contrast ratio of each color filter segment.

In order to improve the contrast ratio of the color filter, it is important to improve the contrast ratio of the yellow filter segment having higher luminance than the red, green, and blue filter segments.
The contrast ratio of the yellow filter segment included in the color filter of the present invention is preferably 2000 or more, more preferably 3000 or more, and further preferably 4000 or more. If the contrast ratio is less than 2000, the contrast ratio of the color filter is low, and the image quality may be insufficient. In addition, the upper limit of the contrast ratio of the yellow filter segment can be increased to the same as the contrast ratio of the polarizing plate (contrast ratio measured without the color filter), and the contrast ratio of the polarizing plate is currently about 15000. is there.

Each color filter segment included in the color filter of the present invention is formed by using a coloring composition containing a transparent carrier, a precursor thereof or a mixture thereof, a coloring matter, and an organic solvent as necessary. Is done.
As the coloring matter contained in the coloring composition, organic or inorganic pigments can be used alone or in admixture of two or more. Among the pigments, pigments having high color developability and high heat resistance, particularly pigments having high heat decomposition resistance are preferred, and organic pigments are usually used.

As the organic pigment contained in the coloring composition, commercially available ones can be used, and dyes, natural pigments, and inorganic pigments can be used in combination according to the hue of the filter segment to be formed. Moreover, an organic pigment etc. can be used individually or in mixture of 2 or more types.
Below, the specific example of the organic pigment which can be used for a coloring composition is shown by a color index (CI) number.

  Yellow pigmented compositions for forming yellow filter segments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 138, 139, 147, 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 1 It can be used yellow pigments such 4,175,176,177,179,180,181,182,185,187,188,193,194,198,199,213,214. In particular, C.I. Pigment Yellow 138, 139, 150, and 185 are preferable from the viewpoint of resistance, brightness, and contrast of the filter segment.

Red pigmented compositions for forming red filter segments include CI Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 122, 123, 146, 149, 168, 177, 178, 179, 184, 185, 187, 192, 200, 202, 208, 210, 216, 220, 223, 224, 226, 240, 254, Red pigments such as 255, 264, and 272 can be used. The red coloring composition can be used in combination with a yellow pigment and an orange pigment used in the yellow coloring composition.
CI Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 etc. are mentioned as an orange pigment.

Green pigments such as CI Pigment Green 7, 10, 36, 37 can be used for the green coloring composition for forming the green filter segment. The green coloring composition can be used in combination with the yellow pigment used in the yellow coloring composition.
The blue coloring composition for forming the blue filter segment includes a blue pigment such as CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 64, 80, etc. Can be used. Further, purple pigments such as CI Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50, preferably CI Pigment Violet 23 can be used in combination with the blue coloring composition. .

The coloring composition can contain an inorganic pigment in order to ensure good coatability, sensitivity, developability and the like while balancing saturation and lightness. Inorganic pigments include titanium oxide, barium sulfate, zinc white, lead sulfate, yellow lead, zinc yellow, red bean (red iron (III) oxide), cadmium red, ultramarine, bitumen, chromium oxide green, cobalt green, amber, titanium Examples thereof include black, synthetic iron black, and carbon black. As the carbon black, any carbon black such as neutral, acidic and basic can be used.
An inorganic pigment is used individually or in combination of 2 or more types. The inorganic pigment can be used in an amount of 0.1 to 10 parts by weight based on the pigment weight of 100 parts by weight.
Moreover, the coloring composition for color filters of this invention can be made to contain a dye within the range which does not reduce heat resistance for color matching. The dye can be used in an amount of 0.1 to 10 parts by weight based on the pigment weight being 100 parts by weight.

The pigment contained in the coloring composition is preferably subjected to a finer treatment and preferably has a large specific surface area in order to achieve high brightness and high contrast of the color filter.
In particular, the specific surface area by the BET method of the yellow pigment contained in the yellow coloring composition, is preferably 90m ² / g or more, more preferably 95 m ² / g or more, more preferably at 100 m ² / g or more is there. Moreover, it is preferable that the specific surface area by BET method of a yellow pigment is 140 m < ² > / g or less. When the specific surface area of the yellow pigment is smaller than the lower limit value, the luminance and contrast ratio of the color filter are lowered. Further, when the specific surface area of the yellow pigment is larger than the upper limit value, it is difficult to disperse the pigment, and it becomes difficult to maintain the stability as the coloring composition and to secure the fluidity. As a result, the luminance and contrast ratio characteristics of the color filter deteriorate.

As a means for controlling the specific surface area of the pigment, a method of controlling the specific surface area by mechanically pulverizing the pigment (referred to as a grinding method), a solution dissolved in a good solvent is introduced into a poor solvent, and a desired specific surface area of the pigment is controlled. There are a method of precipitating a pigment (referred to as a precipitation method), a method of producing a pigment having a desired specific surface area at the time of synthesis (referred to as a synthetic precipitation method), and the like. Depending on the synthesis method and chemical properties of the pigment to be used, an appropriate method can be selected for each pigment.
Each method will be described below, but any of the above methods may be used as a method for controlling the specific surface area of the pigment contained in the colored composition used in the present invention.

  In the grinding method, the pigment is mechanically kneaded with a grinding agent such as water-soluble inorganic salt such as salt and a water-soluble organic solvent that does not dissolve it using a ball mill, sand mill, or kneader (hereinafter, this process is salted). In this method, the inorganic salt and the organic solvent are washed away with water and dried to obtain a pigment having a desired specific surface area. However, since the pigment may crystallize by the salt milling treatment, a method of preventing crystal growth by adding a solid resin or a pigment dispersant that is at least partially dissolved in the organic solvent during the treatment is effective.

As for the ratio of the pigment to the inorganic salt, if the ratio of the inorganic salt is increased, the efficiency of refining the pigment is improved, but the productivity is lowered because the amount of pigment processed is reduced. In general, 1 to 30 parts by weight, preferably 2 to 20 parts by weight of the inorganic salt is used per 1 part by weight of the pigment. Further, the water-soluble organic solvent is added so that the pigment and the inorganic salt are uniformly solidified, and depending on the blending ratio of the pigment and the inorganic salt, the amount of the pigment is usually 50 to 300% by weight. Used.
More specifically, the salt milling is performed by adding a small amount of a water-soluble organic solvent as a wetting agent to a mixture of a pigment and a water-soluble inorganic salt, kneading with a kneader or the like, and then pouring the mixture into water. Stir with a speed mixer to make a slurry. Next, this slurry is filtered, washed with water, and dried to obtain a pigment having a desired specific surface area.

  The precipitation method is a method in which a pigment is dissolved in an appropriate good solvent and then mixed with a poor solvent to precipitate a pigment having a desired specific surface area. The specific surface area depends on the type and amount of the solvent, the precipitation temperature, the precipitation rate, etc. The size of can be controlled. In general, pigments are difficult to dissolve in solvents, so the solvents that can be used are limited, but examples include strongly acidic solvents such as concentrated sulfuric acid, polyphosphoric acid, chlorosulfonic acid, or basic solvents such as liquid ammonia, dimethylformamide solution of sodium methylate, etc. It has been known.

  A typical example of this method is an acid pasting method in which a solution in which a pigment is dissolved in an acidic solvent is poured into another solvent and reprecipitated to obtain fine particles. Industrially, a method of injecting a sulfuric acid solution into water is generally used from the viewpoint of cost. The sulfuric acid concentration is not particularly limited, but is preferably 95 to 100% by weight. The amount of sulfuric acid used with respect to the pigment is not particularly limited. However, if the amount is too small, the solution viscosity is high and handling becomes bad. Conversely, if the amount is too large, the treatment efficiency of the pigment is lowered. It is preferable. The pigment need not be completely dissolved. The temperature at the time of dissolution is preferably from 0 to 50 ° C. Below this temperature, sulfuric acid may freeze and the solubility will be low. If the temperature is too high, side reactions tend to occur. The temperature of the water to be injected is preferably 1 to 60 ° C., and if the injection is started at a temperature higher than this temperature, it boils with the heat of dissolution of sulfuric acid, and the operation is dangerous. It will freeze at temperatures below this. The injection time is preferably 0.1 to 30 minutes with respect to 1 part of the pigment. As the time increases, the specific surface area tends to decrease.

The specific surface area of the pigment can be controlled while considering the fine particle size of the pigment by selecting a method that combines a precipitation method such as the acid pasting method and a grinding method such as the salt milling method. At this time, it is more preferable because fluidity as a dispersion can be secured.
At the time of salt milling or acid pasting, in order to prevent pigment aggregation associated with the specific surface area control, the following dispersion aids such as dye derivatives, resin-type pigment dispersants and surfactants may be used in combination. Further, by controlling the specific surface area in the form of coexisting two or more kinds of pigments, even a pigment that is difficult to disperse alone can be finished as a stable dispersion.

  There is a leuco method as a special precipitation method. When a vat dye, such as a flavantron, perinone, perylene, or indanthrone, is reduced with alkaline hydrosulfite, the quinone group becomes a hydroquinone sodium salt (leuco compound) and becomes water-soluble. A pigment having a large specific surface area that is insoluble in water can be precipitated by adding an appropriate oxidizing agent to the aqueous solution for oxidation.

The synthetic precipitation method is a method in which a pigment having a desired specific surface area is deposited simultaneously with the synthesis of the pigment. However, when the produced fine pigment is taken out of the solvent, if the pigment particles are not aggregated into large secondary particles, filtration, which is a general separation method, becomes difficult. It is applied to azo pigments synthesized in water.
Furthermore, as a means of controlling the specific surface area of the pigment, the pigment can be dispersed at the same time as increasing the specific surface area of the pigment by dispersing the pigment for a long time with a high-speed sand mill or the like (so-called dry milling method in which the pigment is dry pulverized). Is possible.

  The dye carrier contained in the color filter coloring composition of the present invention disperses the dye and is composed of a transparent resin, a precursor thereof, or a mixture thereof. The transparent resin is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin, and its precursor includes a monomer or an oligomer that is cured by irradiation with radiation to form a transparent resin. Alternatively, two or more kinds can be mixed and used.

  The dye carrier can be used in an amount of 30 to 700 parts by weight, preferably 60 to 450 parts by weight, with respect to 100 parts by weight of the dye in the coloring composition. Moreover, when using the mixture of transparent resin and its precursor as a pigment | dye carrier, transparent resin is 20-400 weight part with respect to 100 weight part of pigment | dyes in a coloring composition, Preferably it is 50-250 weight part. Can be used. The precursor of the transparent resin can be used in an amount of 10 to 300 parts by weight, preferably 10 to 200 parts by weight, with respect to 100 parts by weight of the pigment in the colored composition.

Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. And acrylic resins, alkyd resins, polystyrene resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polybutadiene, polyethylene, polypropylene, polyimide resins, and the like.
Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

  Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  Monomers and oligomers that are precursors of transparent resins include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, various acrylic esters such as epoxy (meth) acrylate and methacrylic acid Examples include esters, (meth) acrylic acid, styrene, vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and acrylonitrile.

When the composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the coloring composition.
Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Hydroxycyclohexyl phenyl ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- Acetophenone photopolymerization initiators such as 1-one, benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4 -F Benzophenone photopolymerization initiators such as nylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone Thioxanthone photopolymerization initiators such as 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s- Triazine, 2,4-bis (trichloro Til) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4 , 6-Bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, etc. A polymerization initiator, a borate photopolymerization initiator, a carbazole photopolymerization initiator, an imidazole photopolymerization initiator, or the like is used.
A photoinitiator can be used in the amount of 5-200 weight part with respect to 100 weight part of pigment | dyes in a coloring composition, Preferably it is 10-150 weight part.

The above photopolymerization initiators are used alone or in combination of two or more. As sensitizers, α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone. , Camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, etc. It can also be used together.
The sensitizer can be contained in an amount of 0.1 to 60 parts by weight with respect to 100 parts by weight of the photopolymerization initiator.

Furthermore, the coloring composition can contain a polyfunctional thiol that functions as a chain transfer agent.
The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, tris (2-hydroxyethyl) isocyanurate, trimercaptopropionic acid, 1,4-dimethylmercaptobenzene, 2,4,6-trimerca DOO -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.
The polyfunctional thiol can be used in an amount of 0.2 to 150 parts by weight, preferably 0.2 to 100 parts by weight, with respect to 100 parts by weight of the dye in the coloring composition.

Furthermore, the coloring composition for a color filter of the present invention is obtained by sufficiently dispersing a dye in a dye carrier and applying it on a transparent substrate such as a glass substrate so that the dry film thickness is 0.2 to 5 μm. A solvent can be included to facilitate the formation of the segments.
Examples of the solvent include 1,2,3-trichloropropane, 1,3-butanediol, 1,3-butylene glycol, 1,3-butylene glycol diacetate, 1,4-dioxane, 2-heptanone, and 2-methyl. -1,3-propanediol, 3,5,5-trimethyl-2-cyclohexen-1-one, 3,3,5-trimethylcyclohexanone, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3-methyl -1,3-butanediol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-3-methylbutyl acetate, 3-methoxybutanol, 3-methoxybutyl acetate, 4-heptanone, m-xylene, m -Diethylbenzene, m-dichlorobenzene, N, N-dimethylacetamide, N, N-dimethylformamide, n-butyl alcohol, n-butylbenzene, n-propylacetate N-methylpyrrolidone, o-xylene, o-chlorotoluene, o-diethylbenzene, o-dichlorobenzene, p-chlorotoluene, p-diethylbenzene, sec-butylbenzene, tert-butylbenzene, γ-butyrolactone, isobutyl Alcohol, isophorone, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monotertiary butyl ether, ethylene glycol monobutyl ether, ethylene glycol monobutyl ether acetate , Ethylene glycol monopropyl ether, ethylene glycol monohexyl ether, Ethylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, diisobutyl ketone, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether, cyclohexanol, cyclohexanol Acetate, cyclohexanone, dipropylene glycol dimethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol Monopropyl ether, dipropylene glycol monomethyl ether, diacetone alcohol, triacetin, tripropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, propylene glycol diacetate, propylene glycol phenyl ether, propylene glycol monoethyl ether, propylene glycol monoethyl ether acetate , Propylene glycol monobutyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate, benzyl alcohol, methyl isobutyl ketone, methylcyclohexanol, n-amyl acetate, Acid n- butyl, isoamyl acetate, isobutyl acetate, propyl acetate, dibasic esters, and the like, used alone or in combination.
A solvent can be used in the quantity of 800-4000 weight part with respect to 100 weight part of pigment | dyes in a coloring composition, Preferably it is 1000-2500 weight part.

The coloring composition is a dispersion of three or more roll mills, two roll mills, sand mills, kneaders, attritors, etc. in a dye carrier and an organic solvent together with one or two or more dyes as required. It can be produced by finely dispersing using means. Moreover, the coloring composition containing 2 or more types of pigment | dyes can also mix and manufacture what each disperse | distributed separately in the pigment | dye carrier and the organic solvent separately. When the pigment is dispersed as a pigment in the pigment carrier and the organic solvent, a dispersion aid such as a resin-type pigment dispersant, a surfactant, or a pigment derivative can be appropriately contained. Since the dispersion aid is excellent in dispersing the pigment and has a great effect of preventing re-aggregation of the pigment after dispersion, a coloring composition obtained by dispersing the pigment in a dye carrier and an organic solvent using the dispersion aid is used. If so, a color filter excellent in transparency can be obtained.
The dispersion aid can be used in an amount of 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

  The resin-type pigment dispersant has a pigment-affinity part that has the property of adsorbing to the pigment and a part that is compatible with the dye carrier, and adsorbs to the pigment to stabilize the dispersion of the pigment on the dye carrier. It works. Specific examples of resin-type pigment dispersants include polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamines. Salts, polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, their modified products, amides formed by the reaction of poly (lower alkyleneimines) with polyesters having free carboxyl groups, and the like Water-based dispersants such as oily dispersants such as salts, (meth) acrylic acid-styrene copolymers, (meth) acrylic acid- (meth) acrylic acid ester copolymers, styrene-maleic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone Resin, water-soluble polymer, polyester Modified polyacrylate, ethylene oxide / propylene oxide addition compound, phosphate ester-based and the like are used, they can be used alone or in admixture of two or more.

  Commercially available resin-type pigment dispersants include Disperbyk-101, 103, 107, 108, 110, 111, 116, 130, 140, 154, 161, 162, 163, 164, 165, 166, 170, manufactured by Big Chemie. 171, 174, 180, 181, 182, 183, 184, 185, 190, 2000, 2001, or Anti-Terra-U, 203, 204, or BYK-P104, P104S, 220S, or Lactimon, Lactimon-WS, or Bykumen SOLSPERSE-3000, 9000, 13240, 13650, 13940, 17000, 18000, 20000, 21000, 24000, 26000, 27000, 28000, 31845, 320 manufactured by Abyssia 0, 32500, 32600, 34750, 36600, 38500, 41000, 41090, 53095, etc., EFKA-46, 47, 48, 452, LP4008, 4009, LP4010, LP4050, LP4055, 400, 401, 402 manufactured by Efka Chemicals , 403, 450, 451, 453, 4540, 4550, LP4560, 120, 150, 1501, 1502, 1503, and the like.

  Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, lauryl sulfate monoethanolamine, lauryl Anionic surfactants such as triethanolamine sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate; Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Nonionic surfactants such as alkyl ether phosphates, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; alkyldimethylamino Examples include amphoteric surfactants such as alkylbetaines such as betaine acetate and alkylimidazolines, and these can be used alone or in admixture of two or more.

The pigment derivative is a compound in which a substituent is introduced into an organic dye, and is preferably close to the hue of the pigment to be used. However, if the addition amount is small, those having different hues may be used. Organic dyes also include light yellow aromatic polycyclic compounds such as naphthalene and anthraquinone that are not generally called dyes. Examples of the pigment derivative are described in JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, and the like. You can use what you have. In particular, a pigment derivative having a basic group is preferably used because it has a large pigment dispersion effect. These can be used alone or in admixture of two or more.
Specific examples of the basic group possessed by the pigment derivative include substituents represented by the following general formulas (4), (5), (6) and (7). Among these, a pigment derivative having a basic group containing a triazine skeleton represented by the following general formula (7) is preferably used because of a large pigment dispersion effect.

In the above formulas (4) to (7), X represents —SO ₂ —, —CO—, —CH ₂ NHCOCH ₂ —, —CH ₂ — or a direct bond.
n represents an integer of 1 to 10, preferably an integer of 1 to 3.
R ₁ and R ₂ each independently represent an optionally substituted alkyl group having 1 to 36 carbon atoms, an optionally substituted alkenyl group having 2 to 36 carbon atoms, or an optionally substituted phenyl group. Or R ₁ and R ₂ may combine to form an optionally substituted heterocycle containing additional nitrogen, oxygen or sulfur atoms. R ₁ and R ₂ are preferably unsubstituted or substituted alkyl groups having 1 to 5 carbon atoms.
R ₃ represents an optionally substituted alkyl group having 1 to 36 carbon atoms, an optionally substituted alkenyl group having 2 to 36 carbon atoms, or an optionally substituted phenyl group. R ₃ is preferably an unsubstituted or substituted alkyl group having 1 to 4 carbon atoms.
R ₄ , R ₅ , R ₆ and R ₇ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 36 carbon atoms, an optionally substituted alkenyl group having 2 to 36 carbon atoms, or Represents an optionally substituted phenyl group. R ₄ , R ₅ , R ₆ and R ₇ are preferably unsubstituted or substituted alkyl groups having 1 to 4 carbon atoms.
Y represents —NR ₈ —Z—NR ₉ — or a direct bond.
R ₈ and R ₉ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 36 carbon atoms, an optionally substituted alkenyl group having 2 to 36 carbon atoms, or optionally substituted. Represents a phenyl group. R ₈ and R ₉ are preferably each a hydrogen atom.
Z represents an alkylene group having 1 to 36 carbon atoms which may be substituted, an alkenylene group having 2 to 36 carbon atoms which may be substituted, or a phenylene group which may be substituted. Z is preferably an unsubstituted or substituted phenylene group.

P represents a substituent represented by the following formula (8) or a substituent represented by the following formula (9). In the following formulas (8) and (9), R _{1 to} R ₇ and n are as defined above.
Q represents a hydroxyl group, an alkoxyl group, a substituent represented by the following formula (8) or a substituent represented by the following formula (9). Q is preferably a substituent represented by the following formula (8).

  Examples of the organic dye constituting the pigment derivative having a basic group include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, and polyazo, phthalocyanine dyes, diaminodianthraquinones, anthrapyrimidines, flavantrons, and anants. Anthraquinone dyes such as anthrone, indanthrone, pyranthrone, violanthrone, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes, metal complexes Systematic dyes. Moreover, the organic pigment illustrated previously may be sufficient.

A pigment derivative having a basic group can be synthesized by various synthetic routes. For example, after introducing a substituent represented by the following formulas (10) to (13) into an organic dye, it reacts with the substituent to form a substituent represented by the general formulas (4) to (7). Amine components such as N, N-dimethylaminopropylamine, N-methylpiperazine, diethylamine or 4- [4-hydroxy-6- [3- (dibutylamino) propylamino] -1,3,5-triazine- It can be obtained by reacting 2-ylamino] aniline or the like.
Formula (10) -SO ₂ Cl
Formula (11) -COCl
Equation (12) -CH ₂ NHCOCH ₂ Cl
Equation (13) -CH ₂ Cl

  Examples of the amine component used for forming the substituents represented by the general formulas (4) to (7) include dimethylamine, diethylamine, N, N-ethylisopropylamine, N, N-ethylpropylamine. N, N-methylbutylamine, N, N-methylisobutylamine, N, N-butylethylamine, N, N-tert-butylethylamine, diisopropylamine, dipropylamine, N, N-sec-butylpropylamine, di Butylamine, di-sec-butylamine, diisobutylamine, N, N-isobutyl-sec-butylamine, diamylamine, diisoamylamine, dihexylamine, di (2-ethylhexyl) amine, dioctylamine, N, N-methyloctadecylamine, Didecylamine, diallylamine, N N-ethyl-1,2-dimethylpropylamine, N, N-methylhexylamine, dioleylamine, distearylamine, N, N-dimethylaminomethylamine, N, N-dimethylaminoethylamine, N, N-dimethylamino Amylamine, N, N-dimethylaminobutylamine, N, N-diethylaminoethylamine, N, N-diethylaminopropylamine, N, N-diethylaminohexylamine, N, N-diethylaminobutylamine, N, N-diethylaminopentylamine, N , N-dipropylaminobutylamine, N, N-dibutylaminopropylamine, N, N-dibutylaminoethylamine, N, N-dibutylaminobutylamine, N, N-diisobutylaminopentylamine, N, N-methyl-laurylamino The Pyramine, N, N-ethyl-hexylaminoethylamine, N, N-distearylaminoethylamine, N, N-dioleylaminoethylamine, N, N-distearylaminobutylamine, piperidine, 2-pipecholine, 3-pipecholine, 4 -Pipecoline, 2,4-Lupetidine, 2,6-Lupetidine, 3,5-Lupetidine, 3-Piperidinmethanol, Pipecolic acid, Isonipecotic acid, Methyl isnicopetinate, Ethyl isonicopetic acid, 2-Piperidinethanol, Pyrrolidine, 3-hydroxy Pyrrolidine, N-aminoethylpiperidine, N-aminoethyl-4-pipecholine, N-aminoethylmorpholine, N-aminopropylpiperidine, N-aminopropyl-2-pipecholine, N-aminopropyl-4-pipecholine, N-amino Examples thereof include propylmorpholine, N-methylpiperazine, N-butylpiperazine, N-methylhomopiperazine, 1-cyclopentylpiperazine, 1-amino-4-methylpiperazine, 1-cyclopentylpiperazine and the like. The pigment derivatives can be used alone or in admixture of two or more.

When the organic dye is an azo dye, the basic group is introduced by introducing the substituent represented by the general formulas (4) to (7) into the diazo component or the coupling component in advance and then performing a coupling reaction. An azo pigment derivative having the same can also be produced.
The pigment derivative can be used in an amount of 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the pigment. If the amount is less than 0.1 parts by weight, the effect of dispersing the pigment cannot be obtained, which is not preferable. If the amount is more than 40 parts by weight, the hue may change, which is not preferable.

The coloring composition can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Moreover, in order to improve adhesiveness with a transparent substrate, adhesion improving agents, such as a silane coupling agent, can also be contained.
Examples of storage stabilizers include hydroquinone, such as hydroquinone, methyl hydroquinone, 2,5 di-tert-butyl hydroquinone, tert-butyl hydroquinone, tert-butyl-β benzoquinone, tert-butyl hydroquinone 2,5 diphenyl-p-benzoquinone. Compounds, quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid and their methyl ethers, phosphines such as tributylphosphine, trioctylphosphine, tricyclohexylphosphine, triphenylphosphine and tribenzylphosphine Compounds, phosphine oxide compounds such as trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphite, trisnonyl Examples thereof include phosphite compounds such as phenyl phosphite and t-butylpyrocatechol. The storage stabilizer can be used in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

  Examples of the silane coupling agent include vinyl silanes such as vinyltris (β-methoxyethoxy) silane, vinylethoxysilane, and vinyltrimethoxysilane, (meth) acrylsilanes such as γ-methacryloxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) methyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ) Epoxysilanes such as methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) γ-aminopro Lutriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N Examples include aminosilanes such as -phenyl-γ-aminopropyltriethoxysilane, thiosilanes such as γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane. The silane coupling agent can be used in an amount of 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, with respect to 100 parts by weight of the pigment in the color filter coloring composition.

The coloring composition can be prepared in the form of gravure offset printing ink, waterless offset printing ink, silk screen printing ink, solvent development type or alkali development type coloring resist. The colored resist is obtained by dispersing a dye in a composition containing a thermoplastic resin, a thermosetting resin or a photosensitive resin, a monomer, a photopolymerization initiator, and an organic solvent.
The pigment is preferably contained in a proportion of 5 to 70% by weight based on the total solid content of the colored composition (100% by weight). More preferably, it is contained in a proportion of 20 to 50% by weight, and the remainder consists essentially of a resinous binder provided by a pigment carrier.
The colored composition is removed by means of centrifugal separation, sintering filter, membrane filter, etc. to remove coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably 0.5 μm or more and coarse particles It is preferable to carry out.

The color filter of the present invention comprises a red filter segment, a green filter segment, a blue filter segment, and a yellow filter segment that are formed on the transparent substrate by using the above-described colored compositions by a printing method or a photolithography method. .
As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali alumino borosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate are used. Further, a transparent electrode made of indium oxide, tin oxide, or the like may be formed on the surface of the glass plate or the resin plate for driving the liquid crystal after the liquid crystal panel is formed.

  The formation of each color filter segment by the printing method can be patterned simply by repeating the printing and drying of the colored composition prepared as the above various printing inks. Therefore, the color filter manufacturing method is low-cost and excellent in mass productivity. ing. Furthermore, it is possible to print a fine pattern having high dimensional accuracy and smoothness by the development of printing technology. In order to perform printing, it is preferable that the ink does not dry and solidify on the printing plate or on the blanket. Control of ink fluidity on a printing press is also important, and ink viscosity can be adjusted with a dispersant or extender pigment.

  When each color filter segment is formed by photolithography, the colored composition prepared as the solvent development type or alkali development type color resist is applied on a transparent substrate, such as spray coating, spin coating, slit coating, roll coating, etc. By a method, it apply | coats so that a dry film thickness may be set to 0.2-10 micrometers. When drying the coating film, a vacuum dryer, a convection oven, an IR oven, a hot plate, or the like may be used.

  If necessary, the dried film is exposed to ultraviolet light through a mask having a predetermined pattern provided in contact with or non-contact with the film. Then, after immersing in a solvent or alkali developer or spraying the developer by spraying or the like to remove the uncured portion to form a desired pattern, the same operation is repeated for other colors to produce a color filter. be able to. Furthermore, in order to accelerate the polymerization of the colored resist, heating can be performed as necessary. According to the photolithography method, a color filter with higher accuracy than the above printing method can be manufactured.

In development, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied.
In order to increase the UV exposure sensitivity, after coating and drying the colored resist, a water-soluble or alkaline water-soluble resin such as polyvinyl alcohol or a water-soluble acrylic resin is applied and dried to form a film that prevents polymerization inhibition by oxygen. Thereafter, ultraviolet exposure can also be performed.

  The color filter of the present invention can be produced by an electrodeposition method, a transfer method, an ink jet method or the like in addition to the above method. The electrodeposition method is a method for producing a color filter by using a transparent conductive film formed on a transparent substrate and forming each color filter segment on the transparent conductive film by electrophoresis of colloidal particles. is there. The transfer method is a method in which a color filter layer is formed in advance on the surface of a peelable transfer base sheet, and this color filter layer is transferred to a desired transparent substrate. Further, the ink jet method is a method of manufacturing a color filter by forming each color filter segment by an ink jet method using an ink jet ink.

Next, a liquid crystal display device provided with the color filter of the present invention will be described.
FIG. 3 is a schematic sectional view of a liquid crystal display device provided with the color filter of the present invention. A device 10 shown in FIG. 3 is a typical example of a TFT drive type liquid crystal display device for a notebook personal computer, and includes a pair of transparent substrates 11 and 21 that are arranged to be spaced apart from each other. (LC) is enclosed. The liquid crystal display device provided with the color filter of the present invention includes TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment), OCB (Optically Compensated Birefringence), polymer dispersion. Applicable to liquid crystal displays such as molds.
A TFT (thin film transistor) array 12 is formed on the inner surface of the first transparent substrate 11, and a transparent electrode layer 13 made of, for example, ITO is formed thereon. An alignment layer 14 is provided on the transparent electrode layer 13. A polarizing plate 15 is formed on the outer surface of the transparent substrate 11.

On the other hand, the color filter 22 of the present invention is formed on the inner surface of the second transparent substrate 21. The red, green and blue filter segments constituting the color filter 22 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 22 and further, a transparent electrode layer 23 made of, for example, ITO is formed thereon, and the alignment layer 24 covers the transparent electrode layer 23. Is provided. A polarizing plate 25 is formed on the outer surface of the transparent substrate 21. Note that a backlight unit 30 including a three-wavelength lamp 31 is provided below the polarizing plate 15.
Further, as the backlight included in the liquid crystal display device including the color filter of the present invention, an LED backlight can be used in addition to the cold cathode fluorescent lamp (CCFL) backlight.

Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to the following examples unless it exceeds the gist.
In the examples and comparative examples, “parts” means “parts by weight”.
[Pigment adjustment]
The pigments used in Examples and Comparative Examples are those shown in Table 1, red pigments 2, 4, green pigment 2, yellow pigments 2, 4, 6, 8, and blue pigment 3 prepared as follows. In addition, about the yellow pigment used for the yellow coloring composition, the specific surface area of the BET method by nitrogen adsorption | suction was measured using the automatic vapor | steam adsorption amount measuring apparatus ("BELSORP18" by Nippon Bell Co., Ltd.). The results are shown in Table 2.
In addition, Table 3 shows the dispersants used in Examples and Comparative Examples.

[Red Pigment 2 (R-2)]
136 parts of red pigment 1 (R-1) shown in Table 1, 24 parts of dispersant A-1 shown in Table 3, 1600 parts of sodium chloride, and 190 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) And kneaded at 60 ° C. for 8 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 156 parts of a salt milled pigment (red pigment 2).

[Red Pigment 4 (R-4)]
160 parts of red pigment 3 (R-3) shown in Table 1, 1600 parts of sodium chloride, and 190 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) at 60 ° C. for 12 hours. Kneaded. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 156 parts of a salt milled pigment (red pigment 4).

[Green Pigment 2 (G-2)]
500 parts of green pigment 1 (G-1) shown in Table 1, 1300 parts of sodium chloride, and 270 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) at 70 ° C. for 3 hours. Kneaded. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 496 parts of a salt milled pigment (green pigment 2).

[Yellow Pigment 2 (Y-2)]
280 parts of yellow pigment 1 (Y-1) shown in Table 1, 1400 parts of sodium chloride, and 280 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are charged into a stainless gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) at 60 ° C. for 4 hours. Kneaded. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 277 parts of a salt milled pigment (yellow pigment 2).

[Yellow Pigment 3 (Y-3)]
280 parts of yellow pigment 1 (Y-1) shown in Table 1, 1400 parts of sodium chloride, and 280 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are charged into a stainless gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) at 60 ° C. for 10 hours. Kneaded. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 277 parts of a salt milled pigment (yellow pigment 3).

[Yellow Pigment 4 (Y-4)]
200 parts of yellow pigment 1 (Y-1) shown in Table 1, 10 parts of dispersant A-2 shown in Table 3, 1500 parts of sodium chloride, and 200 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) And kneaded at 60 ° C. for 12 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 207 parts of a salt milled pigment (yellow pigment 4).

[Yellow Pigment 6 (Y-6)]
280 parts of yellow pigment 5 (Y-5) shown in Table 1, 21 parts of dispersant A-2 shown in Table 3, 1400 parts of sodium chloride, and 280 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) And kneaded at 80 ° C. for 8 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 298 parts of a salt milled pigment (yellow pigment 6).

[Yellow Pigment 8 (Y-8)]
170 parts of yellow pigment 7 (Y-7) shown in Table 1, 17 parts of dispersant A-2 shown in Table 3, 1700 parts of sodium chloride, and 170 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) And kneaded at 60 ° C. for 8 hours. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 185 parts of a salt milled pigment (yellow pigment 8).

[Blue Pigment 3 (B-3)]
200 parts of blue pigment 2 (B-2) shown in Table 1, 1600 parts of sodium chloride, and 100 parts of diethylene glycol (manufactured by Tokyo Chemical Industry Co., Ltd.) are charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) at 70 ° C. for 12 hours. Kneaded. Next, this mixture is poured into about 5 liters of warm water, heated to about 70 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, then filtered and washed to remove sodium chloride and diethylene glycol, It was dried at 80 ° C. for 24 hours to obtain 198 parts of a salt milled pigment (blue pigment 3).

[Preparation of acrylic resin solution]
Next, preparation of the acrylic resin solution used in Examples and Comparative Examples will be described. The molecular weight of the resin is a weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography).
370 parts of cyclohexanone was placed in a reaction vessel, heated to 80 ° C. while injecting nitrogen gas into the vessel, and a mixture of the following monomer and thermal polymerization initiator was added dropwise at the same temperature over 1 hour to carry out a polymerization reaction.
Methacrylic acid 20.0 parts
Methyl methacrylate 10.0 parts
n-Butyl methacrylate 35.0 parts
2-hydroxyethyl methacrylate 15.0 parts
2,2'-azobisisobutyronitrile 4.0 parts
20.0 parts of paracylphenol ethylene oxide modified acrylate ("Aronix M110" manufactured by Toa Gosei Co., Ltd.)

After completion of the dropwise addition, the mixture was further reacted at 80 ° C. for 3 hours, and then 1.0 part of azobisisobutyronitrile dissolved in 50 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour. A resin solution was obtained. The weight average molecular weight of the acrylic resin was about 40,000.
After cooling to room temperature, about 2 g of the resin solution was sampled, heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 20% by weight. To prepare an acrylic resin solution.

[Preparation of pigment dispersion]
A mixture having the composition (weight ratio) shown in Table 4 was uniformly stirred and mixed, then dispersed with an Eiger mill for 2 hours using zirconia beads having a diameter of 0.5 mm, and then filtered through a 5 μm filter to prepare a pigment dispersion. .

[Adjustment of coloring composition (hereinafter referred to as resist)]
Next, the mixture having the composition (weight ratio) shown in Table 5 was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain each color resist.

Monomer: Trimethylolpropane triacrylate
(Shin Nakamura Chemical "NK Ester ATMPT")
Photopolymerization initiator: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one (“Irgacure 907” manufactured by Ciba Specialty Chemicals)
Sensitizer: 4,4'-bis (diethylamino) benzophenone
("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.)
Organic solvent: cyclohexanone

[Examples 1 to 18, Comparative Examples 1 to 5]
A color filter was produced by the following method using combinations of color resists shown in Table 6.

[Production of color filter]
First, a red resist was applied to a glass substrate on which a black matrix had been formed in advance by spin coating, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, after cooling the substrate to room temperature, ultraviolet rays were exposed through a photomask using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Further, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to form a striped red filter segment on the substrate.
Next, using a green resist, form a green filter segment in the same way, then use a blue resist to form a blue filter segment, and then use a yellow resist to form a yellow filter segment to obtain a color filter. It was. The formed film thickness of each color filter segment was 1.7 μm.

[Preparation of dry paint film for measuring contrast ratio of each color filter segment]
Each color resist obtained was applied to a glass substrate by spin coating, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature and then exposed to ultraviolet rays using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Thereafter, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to prepare a dry coating film for measuring the contrast ratio of each color filter segment. The film thickness of the dried coating film was 1.7 μm in all cases.

[Production of liquid crystal display devices]
A transparent ITO electrode layer was formed on the obtained color filter, and a polyimide alignment layer was formed thereon. A polarizing plate was formed on the other surface of this glass substrate. On the other hand, a TFT array and a pixel electrode were formed on one surface of another (second) glass substrate, and a polarizing plate was formed on the other surface.
The two glass substrates thus prepared face each other so that the electrode layers face each other, and are aligned using spacer beads while keeping the distance between both substrates constant, and the periphery is left so as to leave an opening for injecting the liquid crystal composition. Sealed with a sealant. A liquid crystal composition was injected from the opening to seal the opening. The liquid crystal display device thus produced was combined with a backlight unit to obtain a liquid crystal panel.
The following evaluation was performed about the color filter obtained by the Example and the comparative example.

[Measurement of chromaticity of parallel transmitted light and orthogonal transmitted light of color filter]
First, as shown in FIG. 4A, the polarizing plates 33 and 35 are overlapped on both sides of the obtained color filter 34, and the polarizing axes of the polarizing plates 33 and 35 are made parallel to each other. Using a color luminance meter BM-5A (manufactured by Topcon Corporation) 32, the chromaticity coordinates (the chromaticity of the parallel transmitted light) of the light 38 that has passed through the other polarizing plate 33 by applying the backlight 37 from the side of 35. Measurement was performed under the condition of 2 ° visual field (CIE1931 color system).
Next, as shown in FIG. 4B, with the polarization axes of the polarizing plates 33 and 35 orthogonal to each other, a backlight 37 is applied from one polarizing plate 35 side, and transmitted through the other polarizing plate 33. The chromaticity coordinates of the light 39 (the chromaticity of the orthogonal transmitted light) were measured with the color luminance meter 32.

The backlight has an emission spectrum as shown in FIG. 1, luminance = 1937 cd / m ² , and chromaticity coordinates (x, y) in the XYZ color system chromaticity diagram are (0.316, 0.301). ), Color temperature = 6525K, and chromaticity deviation duv = −0.0136. The polarizing plate used was NPF-SEG1224DU (manufactured by Nitto Denko Corporation).
Further, Δxy was calculated from the chromaticity (x _P , y _P ) of the parallel transmitted light and the chromaticity (x _C , y _C ) of the orthogonal transmitted light using the formula (1). The results are shown in Table 7, and the chromaticity (x _C , y _C ) of the orthogonal transmitted light is shown in FIGS.

4 (a) and 4 also show the chromaticity (x _P , y _P ) of parallel transmitted light and the chromaticity (x _C , y _C ) of orthogonal transmitted light in a single polarizing plate (without a color filter). The same measurement was performed with the color filter 34 removed from (b), and Δxy was calculated using Equation (1). The results are shown in Table 7, and the chromaticity (x _C , y _C ) of the orthogonal transmitted light is shown in FIGS.

[Contrast ratio measurement of each color filter segment and color filter]
Similar to the measurement of the chromaticity of the parallel transmitted light and the orthogonal transmitted light of the color filter, first, as shown in FIG. 4A, polarizing plates 33 and 35 are superimposed on both sides of the obtained color filter segments and the color filter 34. In the state where the polarizing axes of the polarizing plates 33 and 35 are parallel to each other, the luminance L _P (parallel transmission) of the light 38 that has passed through the other polarizing plate 33 with the backlight 37 applied from the one polarizing plate 35 side. Luminance of light) was measured with a color luminance meter 32.
Next, as shown in FIG. 4B, with the polarization axes of the polarizing plates 33 and 35 orthogonal to each other, a backlight 37 is applied from one polarizing plate 35 side, and transmitted through the other polarizing plate 33. The luminance L _{C of the} light 39 (the luminance of the orthogonal transmitted light) was measured with the color luminance meter 32.

In addition, the parallel transmission light luminance L _P and the orthogonal transmission light luminance L _C in the polarizing plate alone (state excluding the color filter) are shown in FIG. 4A and FIG. It measured similarly.
The contrast ratio was calculated by L _P / L _C using the obtained measurement value. The results are shown in Tables 6 and 7.

[Visibility when the LCD panel displays black]
The produced liquid crystal display device was displayed in black, and the colored state was visually observed. The evaluation rank is as follows, and the results are shown in Table 7.
A: No coloring is observed, and the visibility is very good.
○: Slight coloring is observed, but visibility is good.
Δ: Coloring is observed, but there is no problem in practical use.
X: Coloring is considerably observed and visibility is poor.

As shown in Table 7 and FIGS. 5 and 6, the chromaticity of the orthogonal transmitted light in the polarizing plate alone is extremely blue, but the color filters of Examples 1 to 18 have Δxy of less than 0.260. As a result, the coloration of the liquid crystal panel during black display was low and the visibility was good. In particular, the color filters other than Examples 5 and 6 that satisfy the relationships of formulas (2) and (3) were hardly observed in color during black display, and were excellent in visibility.
On the other hand, the color filters of Comparative Examples 1 to 5 had Δxy of 0.260 or more, and the degree of coloring during black display of the liquid crystal panel was large, resulting in poor visibility. Further, in the color filters of Comparative Examples 1 to 5, the chromaticity (x _C , y _C ) of the orthogonal transmitted light deviated from the chromaticity range of claim 3 as shown in FIG.

The graph which shows the emission spectrum of a backlight. 6 is a graph showing a chromaticity range surrounded by six chromaticities defined in claim 3 of the present invention. 1 is a schematic cross-sectional view illustrating an example of a liquid crystal display device including a color filter of the present invention. Explanatory drawing of the contrast ratio measuring method of this invention. The graph which shows the chromaticity of the orthogonal transmission light in the color filter of Examples 1-6. The graph which shows the chromaticity of the orthogonal transmission light in the color filter of Examples 7-12. The graph which shows the chromaticity of the orthogonal transmission light in the color filter of Examples 13-18. The graph which shows the chromaticity of the orthogonal transmission light in the color filter of Comparative Examples 1-5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 11, 21 ... Transparent substrate 12 ... TFT array 13, 23 ... Transparent electrode 14, 24 ... Orientation layer 15, 25 ... Polarizing plate 22 ... Color filter 30 ... Backlight unit 31 ... Three wavelength lamp 32 ... Color Luminance meter 33, 35 ... Polarizing plate 34 ... Color filter 36 ... Backlight light 37 ... Backlight unit 38 ... Parallel transmitted light 39 ... Orthogonal transmitted light (leakage light)

Claims (7)

In a color filter having red, green, blue and yellow filter segments, the color filter is sandwiched between two polarizing plates, and the chromaticity coordinates (x, y) of the XYZ color system chromaticity diagram are measured. The chromaticity (x _P , y _P ) of the parallel transmitted light and the chromaticity (x _C , y _C ) of the orthogonal transmitted light satisfy the following formula (1) , and the contrast ratio of the blue and yellow filter segments is: A color filter satisfying (2) .
Δxy = [(x _P −x _C ) ² + (y _P −y _C ) ² ] ^1/2 <0.260 (1)

CB / CY ≧ 0.60 (2)
CB: Contrast ratio of blue filter segment
CY: Contrast ratio of yellow filter segment The chromaticities (x _C , y _C ) of the orthogonal transmitted light are chromaticity a (0.180, 0.180) and chromaticity b (0.270, 0) on the xy plane in the XYZ color system chromaticity diagram. .180), a straight line connecting chromaticity b and chromaticity c (0.320, 0.250), a straight line connecting chromaticity c and chromaticity d (0.380, 0.280), chromaticity d And a line connecting chromaticity e (0.400, 0.430), a line connecting chromaticity e and chromaticity f (0.300, 0.350), and a line connecting chromaticity f and chromaticity a. claim 1 Symbol placing color filters, characterized in that in the region. The color filter according to claim 1 or 2 , wherein a contrast ratio of the red and green filter segments satisfies the following expression (3).
CG / CR ≧ 0.60 (3)
CG: Contrast ratio of green filter segment CR: Contrast ratio of red filter segment The color filter according to any one of claims 1 to 3 , wherein a contrast ratio of the color filter is 2000 or more. The color filter according to any one of claims 1 to 4 , wherein a contrast ratio of the yellow filter segment is 2000 or more. The yellow filter segment has at least one selected from CI Pigment Yellow 138, 139, 150, and 185 having a specific surface area of 90 m ² / g or more by a BET method and a dye carrier comprising a transparent resin, a precursor thereof, or a mixture thereof. The color filter according to any one of claims 1 to 5 , wherein the color filter is formed from a yellow coloring composition containing a seed yellow pigment. The liquid crystal display device comprising the color filter according to any one of claims 1-6.

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